字符串处理00000

要看你怎么对待字母，可以写一个函数，用自己需要的字符替代字母（也可以是空字符），函数如下：
Function onlynum(a As String, b As String) As Double
  Dim i As Integer, c As String, d As String
  d = ".0123456789"
  If b <> "" Then b = Val(Left(b, 1))
  For i = 1 To Len(a)
    If InStr(d, Mid(a, i, 1)) > 0 Then
      c = c & Mid(a, i, 1)
    Else
      c = c & b
    End If
  Next
  onlynum = Val(c)
End Function

函数调用示范：
a=onlynum("a1234b.cd233","")  结果：a=1234.233，所有字母都被去掉
a=onlynum("a1234b.cd233","a") 结果：a=12340.00233，所有英文字母被0替代
a=onlynum("a1234b.cd233","5") 结果：a=512345.55233，所有英文字母被5替代